Returns a clean copy of the provided object, in order to JSON.stringify it for example

getCleanObject.js

'use strict';

/**
 * Returns a clean copy of the provided object, in order to JSON.stringify it for example.
 *
 * It removes recursively methods and cyclic objects.
 * Cyclic objects are references to a parent object of the property, for example: a.b.c = a;
 * References to non-parent objects are kept, for example: a.b.c = 'hello'; a.d = a.b;
 * @param any obj Any variable. When obj is not an object, it is returned as-is.
 * @param array parents Parents list, for internal use.
 * @return any The cleaned object
 */
function getCleanObject(obj, parents) {
	if (typeof obj !== 'object') {
		return obj;
	}

	parents = parents || [];
	parents.push(obj);
	var newObject = {};
	for (var name in obj) {
		if (obj.hasOwnProperty(name)) {
			if (typeof obj[name] !== 'function') {
				if (typeof obj[name] === 'object') {
					if (parents.indexOf(obj[name]) === -1) {
						newObject[name] = getCleanObject(obj[name], parents);
					}
				} else {
					newObject[name] = obj[name];
				}
			}
		}
	}
	parents.splice(parents.indexOf(obj), 1);
	return newObject;
}
/*
// Example:
var o = { 'a': 1 };
o.cyclic = o;

o.string = 'in o';
o.func = function() { return 'hello world!'; };  // should be removed
o.objectToKeep = { x: 1, y: 2 };

o.objectWithAFunction = {
	a: 5,
	f: function() { return 'hello'; }  // should be removed
};

o.subCyclic = {
	e: 6,
	parent: o  // should be removed
};

o.objectReferencingObjectToKeep = {
	a: 5,
	f: function() { return 'hello'; },
	notAParent: o.objectToKeep // should be kept
};


o.objectReferencingItself = {
	a: 5,
	f: function() { return 'hello'; }  // should be removed
};
o.objectReferencingItself.me = o.objectReferencingItself;  // should be removed

o.subCyclic = {
	e: 6,
	parent: o  // should be removed
};


// here, o can not be JSON.stringified, as it contains cyclic references
console.log('Object: ', o);

var cleaned = getCleanObject(o);
console.log('Cleaned: ', cleaned);

var j = JSON.stringify(cleaned);
console.log('JSON: ', j);
*/